Cement retainer



E. V. CROWELL CEMENT RETAINER Feb. 7, 1933.

Filed March 17, 1930 INVENTOR. frd M Crowe/ a/w 692M/H 4. a

Patented Feb. 7, 1933 UNITED STATES PATENT vOFI-lola This invention is an im rovement in that type of cement retainer w ich is adapted to be lowered and anchored in well casing with a valvular control for the bore of the retainer permitting flow of cement or circulating fluid into the surrounding well bore but preventing` return iow past the retainer.

It is an object of the invention to positively lock the retainer against axial displacement in either of op osite'directions in the well casing, and to tightly seal the retainer by utilizing the pressure of the flow.

It is a further object of the invention to arrange the valvular control so that it will 5 prevent return flow of the discharged material past the retainer but will permit the discharged material exerting ressure against the sealing medium for tlght y packin oi the retainer.

2 t is a still further object of the invention to provide an engagement between the retainer and a string of tubing whereby the retainer may be conveniently run into the well casing, with said engagement forming a uid tight connection which is readily releasable in order that the tubing ma be elevated with relation to the anchore retainer.

It is a still further object of the invention to uide the string of tubing with relation to t e retainer in order that their fluid tight connection may be readily made, and to provide means whereby the retainer may be slowly run into the well casing without sudden dropging.

Further o jects of the invention will be readily understood from the following description of the accompanying drawing, in which:

Fig. 1 is a front elevation, artly in axial section, showing the retainer eing run into a string of well casing. i

Fig. 2 is a similar view showing the retainer anchored in the casing string.

Figs. 3 and 4 are transverse sections on the lines 3--3 and 4-4respectively of.-.Fig. 2.

The cement retainer is adapted to be run into well casing A by lowering a string of 5o tubing B, and is adapted for positive anchoring against displacement in either of opposite directions at a casing shoe 1 which is 'suspended from the casing string by means of expansible slips 2 mounted on t e retainer and adapted to engage a cooperating annular recess 3 in the bore of the casing shoe. 55 As an instance of this arrangement the recess 3 forms abutment shoulders 4 at its respective axial ends, with said shoulders at right-angles to the axis `of the pleasing, ,and the body 6 of the retainer is annularly 00 grooved at 7 for reception of the expansible slips 2, `so that the slips may-contract in groove 7 for lowering-the retainer into the well casing as shown in Fi 1, and will automatically expand when ahned with recess 3 05 so as to positivel 4lock the retainer against longitudinal disp acement in either of opposite directions inthe casing by the seating of the expanded slips between the right-angular abutment shoulders 4 as shown in Fig. 2.

The slips 2 are preferably arcuate structures recessed a-t their innersurfaces so as to form axially spaced sockets'8 which are adapted to partially house expansion springs 9,and the inner ends of the springs bear against .the base of groove 7 so as to tend to outwardly shift the slips for seating engagement between shoulders 4. The movement of the sli s may be limited by bolts 10 which slidably Et in pockets 11 formed in the outer 80 surfaces of the slips, with the inner ends of the bolts extending through suitable openings at the inner ends of the pockets and threaded into the body 6.

When anchored in the casing shoe, the retainer is packed-oil relative to the casing string A, and for this purpose a packin sleeve .12, preferably of rubber, is mountedv on the body 6 with its ends engaged by cooperating abutments 13-14 which are prefer- '9' ably undercut as shown' at 15 in order to prevent radial displacement of the packing. The abutment 13 may be formed on body 6 above the'groove 7, and in/ order to provide for convenient assembly the abutment 14 is 95 preferably .formed yvon a head 5 which is adapted for detachable connection to the iody 6 by means of a threaded engagement 6.

The retainer has anA axial bore for flow of '10 cement, circulating fluid, etc.; and av valvular control which is mounted inthe bore is adapted to open for downward flow through the retainer and thence through the open lower end of the casing into the surrounding well bore, but is adapted to close againstV return flow past the retainer 'while permittlng the discharged material to exert' pressure against packing sleeve 12 for expanding,

mally yieldably retracted to closed position by a spring 19; and below the valvular control the bore of` body 6` is ported as shown at 20, with the ports communicating with an annular recess 2 1 in the inner periphery of packing sleeve 12 so that the pressure of the flow which is discharged past open valve 18 and through the bore of the retainer is exerted against the packing for expanding it to operative position, and when the valve closes against return ow past the retainer the pressure of the discharged material is still exerted against the packing sleeve through the porlts 20 in order to maintain auid tight sea l The tubing string B releasably engages the retainer so that it may lower the retainer to operative position and may then be readily disengaged for elevation relative to the anchored retainer. As an instance of this arrangement the upper end of the head 5 of the retainer preferably forms a valve seat 22 axially spaced above yvalve 18, and a cooperating valve head 23 which is adapted to form a ground joint with valve seat 22 is suspended from the tubing string B. By the abutment of head 23 against the seat 22 the tubing string B may thus force the retainer downwardly through the casing string A until the retainer anchorsy in casing shoe- 1,

with the ground joint 22-23 maintainingv a iluid tight engagement, which however is readily releasable for elevating the tubing string with relation to 'the anchored retainer.

In order to prevent sudden dropping of the retainer as it is forced downwardly through the casing, frictional retarding means shown as bowed springs 21 are preterably mounted on head 5 so asito yieldably engage the wallof the bore of the casing; and in order to guide the tubing B into axial alinement'with the retainer so as to insure a. tight engagement at ground joint 22-23, similar bowedv springs 25 are preferably mounted on the tubing adjacent the head 23 so that the yieldable frictional engagement of springs 25 with the Wall of the bore of the casing will accurately center the tubing string. The springs 24 and 25 are preferably fixed at one end as shown at 26, and at their opposite ends are adapted for limited axial movement by pin and slot connections 27 in order that the springs may readily yield and expand.

In operation the retainer is forced downwardly through the casing string as shown in Fig. 1 and is then automatically and positively locked in casing shoe 1 by the' engagement of the expanded slips 2 with the shoulders 4 as shown in Fig. 2. The weight ofthe string of tubing then maintains a leakproof engagement at the ground joint 22-23 so that all of the circulating fluid, cement, etc., which is discharged downwardly through the tubing Hows past the open valve 18 and through the bore of the retainer for discharge into the surrounding well bore; and the pressure `of the flow is exerted through ports 2O against the 'pack-ing 12 for expanding it. to operative position so as to tightly seal the retainer against leakage upwardly past the same into the casing string.

lVhen the cementing operation is completed the valve 18 closes against return flow, with the pressure of thedischarged material still directed through ports 2O for maintaining the packing sleeve 12 in operative position; and the tubing string. may then be readily disengaged from the anchored retainer at the ground joint 22- 23 in order that the tubing may be conveniently withdrawn. In the event of leakage past the packing sleeve during the cenienting operation, the ground oint 22-23 also provides for temporary elevation of the tubing string'with relation to the anchored retainer in order that circulating fluid may be' discharged from the tubing into the casing string for flushing out any accumulated cement.

When it is subsequently desired to open the bore of the cemented casing, the anchored retainer is drilled through in usual manner, and for this purpose is made of usual relatively frangib'le material such as cast iron which offers no appreciably obstruction to a usual drill.

The invention thus provides a cement retainer which may be positively locked in place against longitudinal displacement in either of opposite directions, whereby pressure of the flow in either of opposite directions cannot disturb the anchored retainer, but with the pressure of the low adapted to operatively expand a packing element of the retainer so as to form a fluid tight seal, and the anchored retainer readily releasable from the tubing string by which it is lowered to operative position, in order that the tubing may be conveniently elevated and withdrawn.

I claim:

1. In combination, a casing string having an interior annular recess forming axially spaced abutment shoulders at right-angles to means for anchoring the plug in the casing.

string, packing on the plug adapted to engage the wall of the casing string, the plug havlng a borewith ports opening therefrom in back of the packing, and a downwardly opening normally closed valve for said bore, the valve being positioned above said ports.

3. In combinatiomla casing string, a plug adapted to be lowered in the casing string, means for anchoring the plug in the casing string, the plug having a bore, a downwardly opening normally closed valve for Asaid bore, and a tubing string adapted for non-rotary yreadily disengageable fluid tight abutment against the uper end of the it in the casing string. y 4. In combination, a casing string, a plug adapted to be lowered in the'casing string, means for anchoring the plug in the 'casing string, the plug having a bore, a downwardly opening normally closed valve for said bore, and a tubing string having a head adapted for readily disengageable ground joint abutment against the upper end of the plug for loweringit in the casing string.

5. In combination, a casing string, a plug adapted to be lowered in the casing string, means for anchoring the plug in the casing string, packing onvthe plug adapted to engage the wall of the casing string, the plug having a bore with ports openingtherefrom in back of the packing, a downwardly opening normally closed valve Jfor said bore, the valve being positioned above said ports, and a tubing string adapted for readily disengageable Huid tight abutment against the upper end of the plugs for lowering it in the casing string.

6. In combination, a casing string, a plug adapted to be'lowered in the casing string, means for anchoring the plug in the casing string, the plug having a bore, a downwardly opening normally closed valve for said bore, means for frictionally retarding lowering of the plug in the casing string, a tubing string adapted for non-rotary readily disengageable fluid tight abutment against the upper end of the plug for lowering it in the casing string.

7. In combination, a casing string, a plug adapted to be lowered in the casing string, meansforanchoring the plug in the casing string, the plug having a bore, a downwardplug for lowering 1y cpeningnormallyclosed valve for said bore, a tubing strin adapted for non-rotary readily disengagea le Huid tight abutment against the upper end of the plug for lowering it in the casing string, and means on the tubing string engaging the wall of the casing string for alining the tubing string with the plug.

8. A cement retainer comprising a plug l having abore, packing on the plug, ports opening from the bore lof the plug in back of the packing, and a normally clos'ed downwardly opening valve y'for the bore above said ports.l

9. A cement retainer comprising a plug adapted to be lowered in well casing, the plug having a bore, a normally closed downwardly opening valve for lsaid bore, the upper end oif' said bore forming a seat, and a head adapted for suspension from a tubing string for readily releasable ground joint abutment against said seat.

10. A cement retainer comprising a plug adapted to be lowered in well casing, the plug having a bore, packing on'the plug, ports openino' from the bore of the plugin back of the pac-lling, a normally closed downwardly opening valve for the bore above vsaid ports, the upper end of said bore forming a seat, and a head adapted for suspension from a tubing string for readily releasable uid tight abutment against said seat.

11. vA cement retainer comprising a plug adapted to be lowered in well casing, the plug having a bore, a normally closed downwardly opening valve for said bore, the upper end of said bore forming a seat, a head adapted for suspension from a tubing string for non-rotary readily releasable Huid tight abutment against said seat, and means on the plug for frictionally retarding its lowering into lthe well casing.

12. A cement retainer comprising a plug adapted to be lowered in well casing, the plug having a bore, a normally closed downwardly opening valve fo'r said bore, the upper end of said bore forming aseat, a head adapted for suspension from a tubing string for non-rotary readily releasable lluid tight abutment against said'seat, and means on the head for guiding it into alinement with the seat.

13. A cement retainer comprising a plug adapted to be lowered in Well casing, the plug having a bore, a normally closed downwardly opening valve `for Said bore, the upper end of said bore forming a seat, and a head adapted for suspension from a tubingy string for non-rotary readily releasable fluid tight abutment against the seat.

In testimony whereof I have alxed my signature. y

ERD V, CROWELL.v 

